• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.397-398
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• 2011

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.795-800
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• 2014

In this paper, a vibrotactile pad system, T-mobile, is developed to provide vibrotactile cues for hand-held devices. A grooved and slim design is adapted to the back-side plane of the T-mobile, and the contact part consists of 12 vibrotactile panels which can operate independently and separately. To be isolated among vibrotactile actuators, the surface of the cover is divided into several pieces. Each vibrating module consists of a linear resonant actuator, a section of covering surface, and a vibration isolator. In order to provide spatial and directional information, sensory saltation and phantom sensation are applied to the T-mobile. To evaluate the developed device, two experiments were conducted to test whether directional information and spatial information can be successfully displayed by the device. Additionally, in order to find optimal stimulation by sensory saltation, an empirical test was conducted. As a result, spatial and directional information would be useful for displaying intuitive information for hand-held devices with vibrotactile feedback and reasonable near-optimal value for sensory saltation was obtained.

• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.217-227
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• 2013

We introduce a learning system for the sight reading of simple drum sequences. Sight reading is a cognitive-motor skill that requires reading of music symbols and actions of multiple limbs for playing the music. The system provides knowledge of results (KR) pertaining to the learner's performance by color-coding music symbols, and guides the learner by indicating the corresponding action for a given music symbol using additional auditory or vibrotactile cues. To evaluate the effects of KR and guidance cues, three learning methods were experimentally compared: KR only, KR with auditory cues, and KR with vibrotactile cues. The task was to play a random 16-note-long drum sequence displayed on a screen. Thirty university students learned the task using one of the learning methods in a between-subjects design. The experimental results did not show statistically significant differences between the methods in terms of task accuracy and completion time.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.19-26
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• 2006

This paper presents a novel pneumatic tactile display that can deliver some useful information. The air-jet display forms 5 by 5 arrays and features air nozzles with an external diameter of 2.4mm and internal diameter of 1.5 mm. In comparison with other tactile displays such as vibrotactile, there is little concrete psychophysical data relating to pneumatic displays, a fact which hinders their adoption. This paper addresses this challenge, and presents brief psychophysical studies examining localization rate, the two point threshold, stimulus intensity and the temporal threshold of cues produced by pneumatic air jets. Two groups of subjects were used in these studies, subsequently termed groups A and B. Both were comprised of eight participants. In the case of localization study we obtained 58.13% and 85.9% of localization rates each for dense display and sparse display. Two-points threshold test showed the length of gap between two air-jet stimuli which subjects can detect. However, it was formidable to find out precise temporal resolution of PTI owing to the limitation of capability of the pneumatic valves. Lastly, the results of stimulus intensity study suggest that by varying the size of a pneumatically created tactile stimulus, we can effectively vary its perceived magnitude.